Photocatalyst composite and process for producing the same

Photocatalyst complex and its manufacturing method

1 is a view showing changes in weight loss per unit area of an adhesive in a photocatalytic composite by irradiating black light to Samples A and C of Examples and Sample E of Comparative Examples.

<background-art><p>The present invention relates to a photocatalyst complex in which photocatalyst particles are adhered to a substrate and a method for preparing the same.</p><p>When the photocatalytic particles are exposed to irradiation with a wavelength corresponding to more than the band gap energy, phototransition of electrons to the conduction band and the generation of holes in the corresponding valence band occur. The strong reducing power of electrons and the strong oxidizing power of holes generated by this optical transition can be utilized in the decomposition and purification of organic materials as well as the decomposition of water. The photocatalyst particles used in such treatment are usually deposited on a substrate having a size larger than that of the photocatalyst particles to prevent dispersion into the air or release from the system, and to provide easy separation of the photocatalyst from the treatment system. Depositing the photocatalyst particles on the substrate consists of sintering the photocatalyst particles on the substrate at a temperature of 400° C. or higher to adhere the particles to the substrate, or spraying the precursor onto the substrate to a temperature of about 400° C. It can be carried out by a method consisting in adhering the particles to a substrate by heating and converting them to a photocatalyst through pyrolysis. Optionally, methods have been proposed for coagulating photocatalytic particles using certain types of fluorinated polymers. For example, Japanese Patent Laid-Open No. Hei 4-284851 describes a method consisting of thinning a mixture of photocatalyst particles and a fluorinated polymer and compressing the thin plate under pressure. Japanese Patent Application Laid-Open No. Hei 4 - 334552 discloses a method of thermodynamically melting a fluorinated polymer to adhere photocatalyst particles.</p><p>Recently, attempts have been made to use photocatalytic particles for purification and disinfection of wastes as well as decomposition of toxic, odorous and oily substances in wastes routinely produced in a residential environment. Therefore, the photocatalytic particle is expanding its application area. In view of this, there is a need for a method capable of firmly adhering photocatalytic particles onto a substrate, which can be maintained for a long time without losing the photocatalytic action. Unfortunately, the method of the prior art described above exhibits insufficient adhesion under external pressure, so that the sheet is easily cracked, and since it needs to be heated at a high temperature, it is difficult to apply heat to a substrate such as plastic, an office wall and It cannot be used for interior decoration materials such as various surface products. In addition, heat treatment at a high temperature reduces the specific surface area of the photocatalytic particles, resulting in a decrease in their photocatalytic action. more Special devices may be required, such as devices for wet weather, adhesion under pressure or melting under heat.</p></background-art><tech><p>It is an object of the present invention to provide a photocatalyst composite composed of a substrate to which photocatalyst particles are adhered using an adhesive having low degradability.</p><p>Another object of the present invention is to provide a method for preparing a photocatalyst complex.</p><p>Another object of the present invention is to provide a coating composition using a photocatalyst complex.</p><p>The present inventors have conducted research to develop a method for firmly adhering photocatalytic particles onto a substrate over a long period of time without impairing the photocatalytic action of the particles.</p></tech>

<p>As a result, the present invention</p><p>(1) When the photocatalyst particles are adhered to the substrate together with the adhesive, the photocatalytic action of the photocatalyst particles liberates the photocatalyst particles from the substrate and may decompose and deteriorate the adhesive. Adheres the photocatalytic particles without liberation from the substrate by using a small amount of adhesive, and exhibits sufficient photocatalytic action;</p><p>(2) When the amount of photocatalyst particles is 5-98% based on the total volume of the photocatalyst particles and the less degradable adhesive, the photocatalytic action of the photocatalyst complex generating the photocatalyst particles is reduced It can be adhered to the substrate without degradation,</p><p>(3) The use of organic or inorganic adhesives such as fluorinated polymers and silicone-based polymers as low-degradable adhesives causes the most reduced decomposition of the adhesive due to the photocatalytic action of the photocatalytic particles, so that the photocatalyst particles are durable for a long time. fluorinated polymers and fluoroolefins, which are mainly composed of copolymers of vinyl ethers and/or vinyl esters, are preferred,</p><p>(4) the photocatalytic particles are preferably titanium oxide having high photocatalytic action, high chemical stability and non-toxicity,</p><p>(5) Applicable to photocatalytically making various surface products relatively easily, and the method of adhering photocatalytic particles to easily utilize the photocatalytic action in home appliances, preferably as a convenient and easy method, on a substrate After disposing the photocatalyst particles and the low-degradability adhesive, it is composed of a step of solidifying the adhesive, or more specifically, the photocatalyst particles and the low-degradability adhesive are coated with a coating composition containing the photocatalyst particles, the adhesive and the solvent, or sprayed It consists of a step of solidifying the adhesive on the surface of a substrate such as a variety of products after placement.</p><p>That is, an object of the present invention is to provide a photocatalytic complex comprising a substrate to which photocatalytic particles are firmly adhered for a long period of time without losing the photocatalytic action of the particles.</p><p>The present invention is a photocatalyst composite comprising a substrate having photocatalyst particles adhered through an adhesive having a low degradability. As used herein, the term "adhesive with low degradability" refers to adhesion in photocatalytic composites as measured by the method described in Examples below. means an adhesive exhibiting a significant decrease in the degradation rate due to the photocatalytic action by the photocatalytic particles having a weight loss of the agent of 10% or less, preferably 5% or less, more preferably 3% or less, and most preferably 1% or less do. A weight loss of more than 10% means severe degradation of the adhesive and glass of undesirable large amounts of photocatalytic particles. The less degradable adhesive used in the present invention is, for example, water glass, colloidal silica, silicon compounds such as polyorganosiloxane, phosphates such as zinc phosphate, aluminum phosphate, diphosphates, cement, lime, gypsum, enamel frit (enamel frits), glass lining glazes, inorganic adhesives such as plasters, organic adhesives such as fluorinated polymers, silicone-based polymers, etc., and these adhesives can be used in combination of two or more . In particular, inorganic adhesives, fluorinated polymers and silicone-based polymers are preferable in view of their adhesion. The cement used is, for example, quick hardening cement, general cement, medium heat cement, sulfate resistant cement, white cement, ordinary cement such as oil well cement and geothermal well cement, fly-ash cement, There are sulphate slack cement, silica cement, and mixed cements such as blast furnace cement, aluminum cement and the like. Plasters used include, for example, gypsum plaster, plaster, dolomite and the like. The fluorinated polymers used are, for example, polyvinyl fluoride, polyvinylidene fluoride, trifluorinated polyethylene, tetrafluorinated polyethylene, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluorinated ethylene- Polyethylene Copolymer, Trifluorinated Chlorinated Ethylene - Ethyl Rene copolymer, crystalline fluorinated resin such as tetrafluoroethylene - perfluoroalkylvinyl ether copolymer, perfluorocyclo polymer, vinyl ether - fluoroolefin copolymer, vinyl ester - fluoroolefin copolymer, various and crystalline fluorinated resins such as fluorinated elastomers. In particular, vinyl ether-fluoroolefin copolymers and vinyl ester-fluoroolefin copolymers are mainly preferred, since they tend to be less degradable and easy to control. Silicone-based polymers used include linear silicone resins, acrylic-modified silicone resins, and various silicone elastomers.</p><p>As used in the present invention, the term "photocatalytic particle" means that it can exhibit a photocatalytic action upon irradiation with a light beam having a wavelength corresponding to or greater than the band gap energy. The photocatalyst particles used include one or a combination of two or more known metal compound semiconductors such as titanium oxide, zinc oxide, tungsten oxide, iron oxide, strontium titanate, and the like. In particular, titanium oxide exhibiting high photocatalytic action, high chemical stability and non-toxicity is preferable. In addition, V, Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Pt and Au on the surface and/or inside the photocatalytic particle as a second component because of the higher photocatalytic action of the resulting photocatalytic particle. It is preferable to include at least one metal selected from the group consisting of and/or a compound thereof. The metal compound includes, for example, metal oxide, hydroxide, oxyhydroxide, sulfate, halide, nitrate, and even metal ions. The content of the second component may vary depending on its type. Photocatalytic complex containing the metal and/or metal compound Titanium oxide is preferable. The content of the photocatalyst particles is preferably 5 to 98% by volume based on the total amount of the photocatalyst particles and the adhesive having low degradability. A content of photocatalyst particles below the above-defined range tends to undesirably reduce the photocatalytic action of the resulting photocatalyst, whereas a content above the above-described range also undesirably reduces adhesion. When cement or gypsum is used as the less degradable adhesive, the content of the photocatalyst particles is preferably 5 to 40%, most preferably 5 to 25%. Optionally, when an organic or inorganic adhesive other than cement and gypsum is used as the less degradable adhesive, the content of the photocatalyst particles is preferably 20 - 98%, more preferably 50 - 98%, most preferably 70 - 98%.</p><p>The photocatalyst particles used in the present invention may be prepared by any known technique. For example, (1) a method comprising thermally hydrolyzing a titanium compound such as titanium sulfate, titanium chloride, titanium alkoxide, etc., if necessary, in the presence of crystallization nuclei, (2) titanium sulfate, titanium chloride, titanium alkoxy a method characterized by neutralizing a titanium compound such as de and the like by adding an alkali, if necessary, in the presence of crystallization nuclei, (3) a method characterized by oxidizing titanium chloride, titanium alkoxide, etc. in a gas phase; and (4) There are a number of methods including a method characterized by burning or hydrothermal treatment of the titanium oxide produced by one of (1) and (2). In particular, titanium oxide obtained by the method (1) or by hydrothermal treatment at a temperature of 100 DEG C or higher is preferred because of its higher photocatalytic action. The term "titanium oxide" as used in the present invention means, in addition to titanium oxide, so-called titanium oxide hydrate, titanium hydroxide, metatitanate, orthotitanate, titanium hydroxide regardless of its crystal system. As a second component, one or more metals and/or compounds thereof selected from the group consisting of V, Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Pt, and Au are added inside and/or on the surface of the photocatalyst particles. A method characterized in that the metal and/or compound is adsorbed during the preparation of the photocatalyst particles so as to be present in A method characterized by adsorption by using can be used.</p><p>Substrates used in the present invention include inorganic products such as ceramics and glass, plastics, elastomers, organic products such as wood and paper sheets, and metallic products such as aluminum or alloys such as steel. The size and shape of the substrate is not critical. Coated products may also be used.</p><p>In the present invention, since the action of adsorbing the treated material can coexist, it is preferable to attach the photocatalyst particles and the adsorbent onto the substrate through an adhesive having low degradability. The adsorbent used is a general adsorbent such as activated carbon, zeolite, silica gel, and the like. </p><p>In another aspect of the present invention, after a first layer composed of an adhesive containing no photocatalyst particles is provided on a substrate, a second layer composed of an adhesive having low degradability and photocatalytic particles is provided on the first layer. Provision of a first layer that does not contain photocatalytic particles The silver provides a stronger connection between the substrate and the second layer containing the photocatalytic particles, allowing the photocatalytic particles to adhere more firmly over a longer period to the substrate supporting them. Moreover, it is preferable that the first layer contains inorganic particles without photocatalytic action as fillers. The inorganic particles used include titanium oxide, silicon oxide, aluminum oxide, magnesium oxide, and the like, and their surfaces are coated with silicon oxide, aluminum oxide, or zirconium oxide.</p><p>The photocatalyst composite according to the present invention can be prepared by disposing the photocatalyst particles and an adhesive having low degradability on a part or more of a substrate using an adhesive, and then adhering the photocatalyst particles on the substrate by solidifying the adhesive. In the present invention, in particular, a coating composition is prepared by dispersing photocatalyst particles and an adhesive having low degradability in a solvent, and coating or spraying on a substrate to dispose the photocatalyst particles and a low degradability adhesive on at least a part of the substrate. The solvent used includes water and an organic solvent such as toluene, alcohol and the like. The less degradable adhesive contained in the coating composition is preferably soluble in the solvent used. The less degradable adhesive contained in the coating composition is preferably at least one polymer selected from the group consisting of fluorinated polymers and silicone-based polymers. The amount of the photocatalyst particles is 5 - 98 vol %, preferably 20 - 98 vol %, more preferably 50 - 98 vol %, most preferably 70 - 98 vol %, based on the total amount of the photocatalyst particles and the less degradable adhesive. am. Coating compositions can be formulated using crosslinking agents, dispersants and fillers. The crosslinking agent used is usually one of an isocyanate type and a melamine type, and the dispersing agent used has a coupling agent. In particular, the content of the photocatalyst particles in the coating composition is 40 to 98% by volume based on the total amount of the photocatalyst particles and the less degradable adhesive, and it is preferable to prepare the coating composition together with a coupling agent. The amount of the coupling agent to be added is preferably 5 - 50 %, more preferably 7 - 30 %.</p><p>Application of the coating composition is conventional such as dip coating, dip coating, spin coating, blade coating, roller coating, wire bar coating, reversal roll coating or spray coating. This may be accomplished by disposing the photocatalytic particles and the less degradable adhesive on at least a portion of the substrate by coating or spraying according to one of the coating techniques. If necessary, before applying the photocatalyst particles and the less degradable adhesive on the substrate by coating or spraying, an organic adhesive such as an acrylic resin, an epoxy resin, a polyester resin, a melamine resin, a urethane resin, an alkyd resin, or the above-described A first layer is formed by coating or spraying an adhesive having a low degradability as described above on a substrate, and then coating or spraying a coating composition on the first layer to provide a second layer composed of photocatalyst particles and an adhesive having low degradability. . As the organic adhesive, a conventionally used type may be used. </p><p>After coating or spraying, the composition is coagulated to prepare the photocatalytic composite of the present invention. Coagulation can be carried out by drying, ultraviolet irradiation, heating, cooling, or a technique using a crosslinking agent, and can be carried out at a temperature of 400°C or less, preferably from room temperature to 200°C. In this regard, a temperature of 400 DEG C or higher may cause undesirable thermal decomposition of the adhesive in which the photocatalyst particles are liable to liberate. In the present invention, it is preferable to use a method of coagulation using an isocyanate-based and melamine-based crosslinking agent.</p><p>The photocatalyst complex according to the present invention is irradiated with light of a wavelength corresponding to or greater than the band gap energy to purify and disinfect products containing perishable substances, odorous substances and oily substances in the vicinity of the photocatalyst particles, as well as decompose these substances. The radiation used for exposure includes, for example, ultraviolet light such as sunlight, a fluorescent lamp, a black lamp, a halogen lamp, a xenon flash lamp, a mercury lamp, and the like. In particular, light rays containing near-ultraviolet rays of 300 - 400 nm are preferable. The radiation time and intensity with the light beam can usually be determined depending on the amount of material being treated.</p><p>[Example]</p><p>The present invention will be illustrated with reference to the following examples. </p><p><b><u>Example 1</u></b></p><p>Sodium hydroxide was added to an acidic titanium dioxide sol obtained by thermal hydrolysis of titanium sulfate (CS-N, manufactured by Ishihara Sangyo Kaisha, Ltd.) to adjust the pH to 7, followed by filtration and washing. Thereafter, water was added to the resulting titanium oxide wet cake to 100 g/TiO₂ Prepare a slurry of l. Sodium hydroxide was added to this slurry to adjust the pH to 10, and then hydrothermal treatment was performed at 150° C. for 3 hours in an autoclave. After hydrothermal treatment, the slurry was neutralized to pH 7 by adding nitric acid, filtered, and washed with water. After washing, it was dried at 110° C. for 3 hours to obtain titanium oxide.</p><p>Thereafter, the mixture of the composition specified below is shaken in a paint shaker for 3 hours to effect sufficient mixing, and then dispersed to prepare a coating composition. LUMIFRON LF 200C, described below, is a fluorinated polymer mainly composed of a copolymer of vinyl ether and fluoroolefin.</p><p>9.80 g of titanium oxide</p><p>Fluorinated polymer (LUMIFRON LF200C, 0.80 g</p><p> Manufactured by Asahi Glass Co., Ltd.)</p><p>0.16 g of isocyanate based on curing agent</p><p>Titanium coupling agent (PLANEACT 338X, manufactured by Ajinomoto Co., Inc.) 1.00 g </p><p>23.60 ml of toluene</p><p>20 cm of the coating composition of the formulation² After coating on the glass plate of the, and drying at 120 for 20 minutes to prepare a photocatalyst composite of the present invention (Sample A). This sample A had a titanium oxide content of 90% by volume based on the total amount of titanium oxide and the less degradable adhesive.</p><p><b><u>Example 2</u></b></p><p>Using the same titanium oxide as used in Example 1, the mixture of the composition specified below was shaken in a paint shaker for 3 hours to effect sufficient mixing, and then dispersed to prepare a coating composition. </p><p>7.64 g of titanium oxide</p><p>Fluorinated polymer (LUMIFRON LF200C, 2.36 g</p><p> Manufactured by Asahi Glass Co., Ltd.)</p><p>0.47 g hardener-based isocyanate</p><p>Titanium coupling agent (PLANEACT 338X, manufactured by Ajinomoto Co., Inc.) 0.76 g </p><p>22.50 ml of toluene</p><p>20 cm of the coating composition of the formulation² After coating on the glass plate of the, and drying at 120 for 20 minutes to prepare a photocatalyst composite of the present invention (Sample B). This sample B had a content of titanium oxide of 70% by volume based on the total amount of titanium oxide and the less degradable adhesive.</p><p><b><u>Example 3</u></b></p><p>Using the same titanium oxide as used in Example 1, the mixture of the composition specified below was shaken in a paint shaker for 1 hour to effect sufficient mixing, and then dispersed to prepare a coating composition. </p><p>9.8 g of titanium oxide</p><p>2.7 g of inorganic adhesive-based polyorganosiloxane</p><p>(3:1 mixture of T2202A and T2202B, manufactured by Japan Synthetic Rubber Co., Ltd.)</p><p>21.5 ml isopropyl alcohol </p><p>20 cm of the coating composition of the formulation² After coating on the glass plate of and dried for 10 minutes to prepare a photocatalyst composite (Sample C) of the present invention. This sample C had a titanium oxide content of 90% by volume based on the total amount of titanium oxide and low degradable adhesive.</p><p><b><u>Example 4</u></b></p><p>Sodium hydroxide was added to an acidic titanium dioxide sol obtained by thermal hydrolysis of titanium sulfate (CS-N, manufactured by Ishihara Sangyo Kaisha, Ltd.) to adjust the pH to 7, followed by filtration and washing. Thereafter, the resulting titanium oxide wet cake was dried at 110 DEG C for 3 hours to obtain titanium oxide.</p><p>The mixture of the compositions specified below is shaken in a paint shaker for 3 hours to effect sufficient mixing, and then dispersed to prepare a coating composition. </p><p>7.0 g of titanium oxide</p><p>4.3 g of inorganic adhesive-based polyorganosiloxane</p><p>(3:1 mixture of T2202A and T2202B, manufactured by Japan Synthetic Rubber Co., Ltd.)</p><p>22.5 ml of isopropyl alcohol</p><p>20 cm of the coating composition of the formulation² After coating on the glass plate of the, and then dried at 180 for 10 minutes to prepare a photocatalyst composite of the present invention (Sample D). This sample D had a titanium oxide content of 80% by volume based on the total amount of titanium oxide and low degradable adhesive.</p><p><b><u>Comparative Example 1</u></b></p><p>Using the same titanium oxide as used in Example 1, the mixture of the composition specified below was shaken in a paint shaker for 1 hour to effect sufficient mixing, and then dispersed to prepare a coating composition.</p><p>9.8 g of titanium oxide</p><p>0.7 g of vinyl acetate-acrylic copolymer</p><p>(BONCOAT 6290, manufactured by Dainippon Ink Chemicals, Inc.)</p><p>24.8 ml of water </p><p>20 cm of the coating composition of the formulation² After coating on the glass plate of the, and then dried at 120 for 10 minutes to prepare a photocatalyst composite of the present invention (Sample E). This sample E had a titanium oxide content of 90% by volume based on the total amount of titanium oxide and low degradable adhesive. </p><p>The photocatalyst complexes (Samples A - E) obtained in Examples and Comparative Examples were applied on the surface of each sample with an ultraviolet intensity of 7 mW/cm² exposed to black light. The weight loss is determined by weighing the weight of the adhesive in the photocatalyst composite before and after irradiating black light. As a result, no weight loss indicative of decomposition of the adhesive was observed in samples A-D of the present invention. However, Sample E of Comparative Example in which no adhesive with low degradability was used shows a weight loss of 85%, indicating that most of the adhesive is decomposed by the photocatalytic action of titanium oxide. It can also be observed that sample E becomes yellow and the titanium oxide particles are partially liberated. each sample A of the examples and Fig. 1 shows the change in weight loss in the photocatalyst composite by irradiating black light to sample E of C and Comparative Example. Each of the samples A and B of Examples 1 and 2 contained a coupling agent that was adsorbed on the surface of the photocatalyst particles to form a bridge between the low-degradable adhesive and the photocatalyst particles, so that the photocatalyst particles less degrade the low-degradable adhesive direct contact can be avoided.</p><p>Next, each sample A - D of the present invention is put into a 3 liter glass container, acetaldehyde as a malodorous component is added to the container at a concentration of 90 ppm, and then the container is sealed. Then, the vessel was placed on the surface of each sample with an ultraviolet intensity of 14 mW/cm²of a mercury lamp for 60 min. After irradiation, the concentration of acetaldehyde in the glass container is measured. A result is shown in Table 1. Samples A - D show effective decomposition of acetaldehyde due to the photocatalytic action of titanium oxide.</p><p><tables id="1"><table cols="3" id="1"><row><entry he="257" wi="1793" ce="1" cb="1" re="1" rb="1" al="c"></entry><entry he="257" wi="1102" ce="2" cb="2" re="1" rb="1" al="c">Sample</entry><entry he="257" wi="3683" ce="3" cb="3" re="1" rb="1" al="c"> Concentration of Acetaldehyde (ppm)</entry><row><entry he="127" wi="1793" ce="1" cb="1" re="2" rb="2" al="c">Example 1</entry><entry he="127" wi="1102" ce="2" cb="2" re="2" rb="2" al="c">A</entry><entry he="127" wi="3683" ce="3" cb="3" re="2" rb="2" al="c">0.5 </entry><row><entry he="127" wi="1793" ce="1" cb="1" re="3" rb="3" al="c">Example 2</entry><entry he="127" wi="1102" ce="2" cb="2" re="3" rb="3" al="c">B</entry><entry he="127" wi="3683" ce="3" cb="3" re="3" rb="3" al="c">0.5 </entry><row><entry he="127" wi="1793" ce="1" cb="1" re="4" rb="4" al="c">Example 3</entry><entry he="127" wi="1102" ce="2" cb="2" re="4" rb="4" al="c">C</entry><entry he="127" wi="3683" ce="3" cb="3" re="4" rb="4" al="c">30.0 </entry><row><entry he="124" wi="1793" ce="1" cb="1" re="5" rb="5" al="c">Example 4</entry><entry he="124" wi="1102" ce="2" cb="2" re="5" rb="5" al="c">C</entry><entry he="124" wi="3683" ce="3" cb="3" re="5" rb="5" al="c">0.5 </entry></row></row></row></row></row></table></tables></p><p><b><u>Example 5</u></b></p><p>Sodium hydroxide was added to an acidic titanium dioxide sol obtained by thermal hydrolysis of titanium sulfate (CS-C, manufactured by Ishihara Sangyo Kaisha, Ltd.) to adjust the pH to 7, followed by filtration, washing, drying, and pulverization to titanium oxide to manufacture 0.2 g titanium oxide, 0.8 g white cement (manufactured by Onoda Cement Co., Ltd.) and 0.7 g water 50cm in area in the whole² Coated on a glass plate of, and dried at room temperature to prepare a photocatalyst composite of the present invention (Sample F). This sample F had a titanium oxide content of 17% by volume based on the total amount of titanium oxide and less degradable adhesive.</p><p><b><u>Example 6</u></b></p><p>The same method as in Example 5 was repeated except for using 0.8 g of DENCA high alumina cement (Hi, manufactured by DENKI KAGAKU KOGYO KK) in place of the white cement to prepare a photocatalyst composite of the present invention (Sample G). This sample G had a titanium oxide content of 17% by volume based on the total amount of titanium oxide and less degradable adhesive.</p><p><b><u>Comparative Example 2</u></b></p><p>1.0 g of the same cement as used in Example 5 and 0.7 g of water were mixed, and the total area was 50 cm² Sample H was prepared by coating and drying on a glass plate of</p><p><b><u>Comparative Example 3</u></b></p><p>1.0 g DENCA high alumina cement as used in Example 6 and 0.7 g water were mixed and the total area was 50 cm² Sample I was prepared by coating and drying on a glass plate of</p><p>Each sample F - I of Examples and Comparative Examples was placed in a 4 liter container, and standard nitrogen monoxide gas was injected into the container. Then, the vessel was placed on the surface of each sample with an ultraviolet intensity of 1 mW/cm²exposure to the black light of the NOx sensor (11L, GASTEC Co. Ltd.) is used to measure with time. A result is shown in Table 2. Samples F and G of Examples 5 and 6 cause a large decrease in NOx gas concentration, whereas Samples H and I of Comparative Examples 2 and 3 show little change in NOx gas concentration. From this point of view, the photocatalyst of the present invention is effective in removing nitrogen monoxide by oxidation thereof. To determine the weight loss of cement in the method described above, the weight of cement in each of samples F and G is measured. No weight loss was observed, indicating no degradation of the cement.</p><p><tables id="2"><table cols="6" id="2"><row><entry he="250" wi="1457" ce="1" cb="1" re="2" rb="1" al="c"></entry><entry he="250" wi="1018" ce="2" cb="2" re="2" rb="1" al="c">Sample</entry><entry he="124" wi="4587" ce="6" cb="3" re="1" rb="1" al="c">NOx concentration (ppm)</entry><row><entry he="127" wi="1049" ce="3" cb="3" re="2" rb="2" al="c">0 minute</entry><entry he="127" wi="1222" ce="4" cb="4" re="2" rb="2" al="c">10 minute</entry><entry he="127" wi="1143" ce="5" cb="5" re="2" rb="2" al="c">20 minute</entry><entry he="127" wi="1174" ce="6" cb="6" re="2" rb="2" al="c">30 minute</entry><row><entry he="127" wi="1457" ce="1" cb="1" re="3" rb="3" al="c">Example 5</entry><entry he="127" wi="1018" ce="2" cb="2" re="3" rb="3" al="c">F</entry><entry he="127" wi="1049" ce="3" cb="3" re="3" rb="3" al="c">18.8 </entry><entry he="127" wi="1222" ce="4" cb="4" re="3" rb="3" al="c">8.9 </entry><entry he="127" wi="1143" ce="5" cb="5" re="3" rb="3" al="c">3.1 </entry><entry he="127" wi="1174" ce="6" cb="6" re="3" rb="3" al="c">1.2 </entry><row><entry he="127" wi="1457" ce="1" cb="1" re="4" rb="4" al="c">Example 6</entry><entry he="127" wi="1018" ce="2" cb="2" re="4" rb="4" al="c">G</entry><entry he="127" wi="1049" ce="3" cb="3" re="4" rb="4" al="c">13.5 </entry><entry he="127" wi="1222" ce="4" cb="4" re="4" rb="4" al="c">0.3 </entry><entry he="127" wi="1143" ce="5" cb="5" re="4" rb="4" al="c">0 </entry><entry he="127" wi="1174" ce="6" cb="6" re="4" rb="4" al="c">0 </entry><row><entry he="127" wi="1457" ce="1" cb="1" re="5" rb="5" al="c">Comparative Example 2</entry><entry he="127" wi="1018" ce="2" cb="2" re="5" rb="5" al="c">H</entry><entry he="127" wi="1049" ce="3" cb="3" re="5" rb="5" al="c">15.5 </entry><entry he="127" wi="1222" ce="4" cb="4" re="5" rb="5" al="c">13.5 </entry><entry he="127" wi="1143" ce="5" cb="5" re="5" rb="5" al="c">13.5 </entry><entry he="127" wi="1174" ce="6" cb="6" re="5" rb="5" al="c">13.5 </entry><row><entry he="124" wi="1457" ce="1" cb="1" re="6" rb="6" al="c">Comparative Example 3</entry><entry he="124" wi="1018" ce="2" cb="2" re="6" rb="6" al="c">I</entry><entry he="124" wi="1049" ce="3" cb="3" re="6" rb="6" al="c">13.5 </entry><entry he="124" wi="1222" ce="4" cb="4" re="6" rb="6" al="c">13.2 </entry><entry he="124" wi="1143" ce="5" cb="5" re="6" rb="6" al="c">10.6 </entry><entry he="124" wi="1174" ce="6" cb="6" re="6" rb="6" al="c">10.6 </entry></row></row></row></row></row></row></table></tables></p><p><b><u>Example 7 </u></b></p><p>The coating composition obtained by repeating the same method as in Example 1 was coated with a surface area of 100 cm² A photocatalyst composite of the present invention (Sample J) was prepared by coating on a transparent acrylic plate of , and drying at 120° C. for 20 minutes. This sample J had a titanium oxide content of 90% by volume, based on the total amount of titanium oxide and less degradable adhesive.</p><p><b><u>Comparative Example 4</u></b></p><p>The same acrylic plate as used in Example 7 was used as Sample K.</p><p>Each of the samples J and K in the above examples and comparative examples was placed on the inner wall of a 50 liter water tank. put it in 45 liters of water and 20 goldfish (Wakin) are put in a water tank, and light is irradiated from the outside by a 20 W fluorescent lamp.</p><p>After raising the goldfish for 2 weeks, algae were deposited on the surface of Sample K of Comparative Example 4, whereas no algae were observed on the surface of Sample J of Example 7. This is because even when algae are deposited on the surface of Sample J of Example 7, they are immediately removed by the photocatalytic action. In the method described above, the weight loss of the fluorinated polymer in sample J is determined. No weight loss is observed indicative of degradation of the fluorinated polymer.</p><p><b><u>Example 8</u></b></p><p>The mixture of the composition specified below was shaken in a paint shaker for 1 hour to effect sufficient mixing, dispersed to prepare a coating composition, and coated on a transparent acrylic plate using a spin coater (1000 rpm x 10 sec), and its The same method as in Example 7 was repeated except that the resultant transparent acrylic plate having a first layer composed of a low degradable adhesive material having no photocatalyst particles present on the surface thereof was used as a substrate, and the photocatalyst of the present invention (Sample L) ). The content of titanium oxide in the photocatalyst particles in the second layer of sample L is 90% by volume based on the total amount of titanium oxide and low degradable adhesive.</p><p>3.3 g of titanium oxide without photocatalysis</p><p>(CR-90, manufactured by Ishihara Sangyo Kaisha, Ltd.)</p><p>Fluorinated polymer (LUMIFRON LF200C, 5.5 g</p><p> Manufactured by Asahi Glass Co., Ltd) </p><p>1.1 g of isocyanate based on curing agent</p><p>20.7 ml of toluene</p><p>Measurement of the weight loss of the adhesive used for sample L in the above method indicates that there is no change in the weight of sample L of the present invention, the adhesive does not decompose and the titanium oxide photocatalyst particles are not liberated from the substrate. The film strength of Sample L of Example 8 was 3 H as pencil hardness, indicating that the photocatalyst particles were firmly adhered. Furthermore, the sample L was placed in running water, and the UV intensity from the outside was 2 mW/cm² irradiated with black light for 3 weeks. However, no liberation of titanium oxide catalyst particles was observed in the substrate.</p><p><b><u>Example 9</u></b></p><p>A photocatalyst composite (Sample M) of the present invention was prepared by repeating the same method as in Example 1, except that titanium oxide particles coated with a zinc compound were used instead of titanium oxide. The content of the photocatalyst titanium oxide particles coated with the zinc compound in this sample M was 90% by volume based on the total amount of the photocatalyst particles and the low degradable adhesive.</p><p>Titanium oxide particles coated with a zinc compound are prepared as follows:</p><p>Water and sodium hydroxide were added to a slurry of titanium oxide obtained by thermal hydrolysis of titanium sulfate, so that the pH was 10 and TiO₂ Slurry having 100 g/ in conversion to to form This slurry was hydrothermally treated in an autoclave at 150° C. for 5 hours, neutralized with nitric acid, filtered and washed with water. TiO by adding water to the resulting titanium oxide wet cake₂ to prepare a slurry containing 100 g/L. Hydrochloric acid is added to the resulting slurry to form a slurry of pH 4. To 1 liter of this slurry under stirring, 7.2 ml of a 1 mol/L zinc chloride aqueous solution is added dropwise. Then, the slurry is neutralized with 2N sodium hydroxide solution, filtered and washed with water. Thereafter, the resulting product was dried at 120° C. for 16 hours and ground to ZnO:TiO thereon.₂ Titanium oxide particles containing a zinc compound having a ratio of 1:99 are formed.</p><p><b><u>Example 10</u></b></p><p>The same method as in Example 1 was repeated except that titanium oxide particles coated with an iron compound were used instead of titanium oxide to prepare a photocatalyst composite (Sample N) of the present invention. The content of the photocatalyst titanium oxide particles coated with the zinc compound in this sample N was 90% by volume based on the total amount of the photocatalyst particles and the low degradable adhesive.</p><p>Titanium oxide particles coated with an iron compound are prepared as follows:</p><p>100 g/TiO using 10 g titanium oxide obtained by thermal hydrolysis of titanium sulfate₂ l to form a slurry. To this slurry, 2.9 ml aqueous iron chloride solution with a concentration of 5 g/l (FeCl₃H₂O) was added and stirring was continued for 1 hour. A diluted aqueous ammonia solution is added to this slurry to adjust the pH to 7 . After stirring the slurry for 1 hour, The slurry was filtered, washed with water and dried at 110° C. for 3 hours to obtain titanium oxide particles coated with an iron compound.</p><p>These titanium oxide particles are Fe/TiO₂contains an iron compound of 300 ppm. </p><p><b><u>Example 11</u></b></p><p>The same method as in Example 10 was repeated except that the concentration of the aqueous iron chloride solution was 50 g/l to prepare a photocatalyst (Sample 0) of the present invention. The content of the photocatalytic titanium oxide particles coated with an iron compound in this sample O was 90% by volume based on the total amount of the photocatalytic particles and the low degradable adhesive.</p><p>These titanium oxide particles are Fe/TiO₂ contains 3000 ppm of iron compounds. </p><p><b><u>Example 12</u></b></p><p>8.9 g TiO₂ and 0.5 g of activated carbon, except that the same method as in Example 1 was repeated to prepare a photocatalyst (Sample P) of the present invention. It is 90% by volume based on the total amount of titanium oxide, activated carbon and less degradable adhesive based on the total amount of activated carbon and titanium oxide in this sample P.</p><p><b><u>Example 13</u></b></p><p>A photocatalytic composite according to the present invention (Sample Q) was prepared by repeating the same method as in Example 12, except that the activated carbon was replaced with 0.8 g of zeolite. The total amount of titanium oxide and zeolite is 90% by volume based on the total amount of titanium oxide, zeolite and less degradable adhesive.</p><p>The observation of less degradable adhesives in each sample L-Q indicates no weight loss. In other words, in each sample L - Q, the less degradable adhesive did not decompose, indicating that the titanium oxide particles were not released from the substrate.</p><p>Next, each of the samples A, N and O of the present invention are put in a 0.8 liter glass container, and acetaldehyde as a malodorous component is added to the container so that the concentration is 100 ppm, and then the container is sealed. After that, the container was left for 30 minutes, and the UV intensity of 1 mW/cm was applied to the surface of each sample.² Irradiated with black light of After irradiation, the concentration of acetaldehyde in the glass container is measured. A result is shown in Table 3. Samples A, N and O effectively decompose acetaldehyde by the photocatalytic action of titanium oxide.</p><p><tables id="3"><table cols="3" id="3"><row><entry he="243" wi="1520" ce="1" cb="1" re="1" rb="1" al="c"></entry><entry he="243" wi="1082" ce="2" cb="2" re="1" rb="1" al="c">Sample</entry><entry he="243" wi="3350" ce="3" cb="3" re="1" rb="1" al="c">Concentration of acetaldehyde (ppm)</entry><row><entry he="127" wi="1520" ce="1" cb="1" re="2" rb="2" al="c">Example 1</entry><entry he="127" wi="1082" ce="2" cb="2" re="2" rb="2" al="c">A</entry><entry he="127" wi="3350" ce="3" cb="3" re="2" rb="2" al="c">10.5 </entry><row><entry he="127" wi="1520" ce="1" cb="1" re="3" rb="3" al="c">Example 10</entry><entry he="127" wi="1082" ce="2" cb="2" re="3" rb="3" al="c">N</entry><entry he="127" wi="3350" ce="3" cb="3" re="3" rb="3" al="c">2.0 </entry><row><entry he="124" wi="1520" ce="1" cb="1" re="4" rb="4" al="c">Example 11</entry><entry he="124" wi="1082" ce="2" cb="2" re="4" rb="4" al="c">O</entry><entry he="124" wi="3350" ce="3" cb="3" re="4" rb="4" al="c">0.4 </entry></row></row></row></row></table></tables></p><p>Thereafter, samples M, P and Q are each separately placed in a 0.8 liter glass container. Add malodorous methyl mercaptan to a glass container to a concentration of 500 ppm. After that, the container is sealed. After leaving the container for 2 hours, the UV intensity of 1 mW/cm was applied to the surface of each sample.² Irradiated with black light of After irradiation, the concentration of methyl mercaptan in the glass container is measured. A result is shown in Table 4. Through Table 4, samples M, P and Q effectively remove methylmercaptan by the action of photocatalytic particles. it can be clearly seen that</p><p><tables id="4"><table cols="3" id="4"><row><entry he="124" wi="1912" ce="1" cb="1" re="1" rb="1" al="c"></entry><entry he="124" wi="2035" ce="2" cb="2" re="1" rb="1" al="c">Sample</entry><entry he="124" wi="4682" ce="3" cb="3" re="1" rb="1" al="c">Concentration of methylmercaptan (ppm)</entry><row><entry he="127" wi="1912" ce="1" cb="1" re="2" rb="2" al="c">Example 9</entry><entry he="127" wi="2035" ce="2" cb="2" re="2" rb="2" al="c">M</entry><entry he="127" wi="4682" ce="3" cb="3" re="2" rb="2" al="c">72 </entry><row><entry he="127" wi="1912" ce="1" cb="1" re="3" rb="3" al="c">Example 12</entry><entry he="127" wi="2035" ce="2" cb="2" re="3" rb="3" al="c">P</entry><entry he="127" wi="4682" ce="3" cb="3" re="3" rb="3" al="c">90 </entry><row><entry he="124" wi="1912" ce="1" cb="1" re="4" rb="4" al="c">Example 13</entry><entry he="124" wi="2035" ce="2" cb="2" re="4" rb="4" al="c">Q</entry><entry he="124" wi="4682" ce="3" cb="3" re="4" rb="4" al="c">125 </entry></row></row></row></row></table></tables></p><p>In the above irradiation, the concentration of methyl mercaptan in the container left for 2 hours without ultraviolet irradiation was 250 ppm for each sample. The concentration of methyl mercaptan in the container which was further left for 1 hour without ultraviolet irradiation was 240 ppm for samples M and Q and 220 ppm for sample P.</p>

<p>The photocatalyst composite of the present invention is composed of a substrate containing photocatalyst particles adhered through an adhesive having low degradability, and hardly causes decomposition of the adhesive due to the photocatalytic action. The present invention allows for a robust adhesion of photocatalytic particles on a substrate without losing the photocatalytic action. Utilization of the photocatalyst complex of the present invention enables effective and rapid removal of perishable substances, odorous substances, oily compositions, bacteria, actinomycetes, molds, algae, and the like. Therefore, the photocatalytic composite is very useful as a deodorant and disinfectant in homes and factories. In addition, the photocatalyst composite of the present invention can be used for a long time, has high stability, can be used in a wide range of perishable materials, and can be used without polluting the environment. Therefore, it is industrially useful. In the method for producing a photocatalyst composite according to the present invention, degradability The use of this less adhesive fluorinated polymer makes it possible to prepare desirable photocatalytic composites, and due to the weak adhesion of the fluorinated polymer, it is less prone to adsorb dust and contaminants on its surface.</p><p>The method for preparing the photocatalyst complex of the present invention can use a material such as plastic as a substrate, and is a useful method for conveniently and easily preparing a homogeneous photocatalyst complex.</p><p>By coating or spraying the coating composition of the present invention on any type of substrate or on a desired surface thereof, the photocatalytic action can be easily utilized. Therefore, it is particularly useful for home use.</p>